Figure 415

Length of the loops of Henle in animals correlated with kidney concentrating capacity. A, Investigations of animal species [14] with different lengths of the loops of Henle and correlation with the concentrating capacity of their kidneys reveal their relationship. B, Desert animals with very long loops of Henle can produce highly concentrated urine; in contrast, beavers living in water-rich surroundings have only short loops of Henle and cannot produce urine concentrate over 450 mOsm.